Material coating device

ABSTRACT

A material application apparatus  10  comprises a base  11  on which a workpiece W is placed, a syringe  13  that applies a material onto a movement track L, a movement structure  14  that moves the syringe  13  in three orthogonal axes directions, a rotation mechanism  15  that rotates the syringe  13  around the axis line of the syringe  13 , and a control unit  17  that controls the movement structure  14  and the rotation mechanism  15  in accordance with a configuration of the track L. The syringe  13  includes a nozzle  19  provided to the front-end side of a main body  18  that contains a sealing agent or a material of resin used as an adhesive agent or the like. The discharge port  21  of the nozzle  19  is formed into a generally acute-angled triangle configuration to discharge the material so that a bead B having a sectional configuration in which the height is larger than 0.9 compared to the width of 1 can be formed. Also, the nozzle is adapted so as to be rotated in the periphery direction thereof by a motor M.

TECHNICAL FIELD

The present invention relates to a material application apparatus, andin particular, to a material application apparatus capable of reliablyforming a bead, which allows a desired deformation with a low pressureforce, on a surface to be applied of a workpiece; and, when changing theapplication direction using a nozzle with a non-circular discharge port,capable of rotating the nozzle at a high speed in the peripherydirection thereof.

BACKGROUND ART

As for a material application apparatus for applying a resin material tothe surface of a workpiece, conventionally, for example, a materialapplication apparatus is known, which, to the peripheral area of a mainbody case of a hard disk as the surface, applies a sealing agent onto atrack generally along the periphery of the main body case. The materialapplication apparatus comprises a syringe equipped with a nozzle capableof discharging the sealing agent, and a movement means such as a robotwhich moves the syringe along a predetermined movement track, which hasbeen taught beforehand. The nozzle is formed with a discharge porthaving a generally circular opening at the front-end thereof, movesalong the movement track while discharging the sealing agent from thedischarge port, and thereby the sealing agent is applied to the mainbody case; and as a result, a generally dome-like shaped bead having aflattened sectional configuration is formed. The main body case, onwhich the bead of the shape is formed, is overlapped with a cover, andis secured with screws at several points from the outside of the coverto integrate the cover with the main body case. In this case, the beadis pressed from the top by the cover, and the bead is interposed betweenthe case main body and the cover accompanying a deformation due to thepressure.

However, in the material application apparatus, since a generallydome-like shaped bead having a flattened sectional configuration isformed, amount of deformation at the top side of the bead is smallresulting in such problem that, in a state that a cover is attached tothe case main body, the sealing performance there between gets easilydecreased. Particularly, in the area of the cover away from the screwedpoints or the like, the problem arises more seriously since the pressureforce to the bead becomes lower than that of the areas of the cover nearthe screwed point. On the other hand, when the screw force to the coveris increased in order to increase the pressure force to the bead in theareas of the cover away from the screwed points, another kind of problemarises such that an excess pressure force is given to the bead near thescrewed points resulting in easy cut off of the bead in the area.

Accordingly, the inventor has discovered that, in the above-describedcase, it is preferred to adopt a sectional configuration of the beadthat allows an effective deformation with a low-pressure force. That isto say, a sectional configuration of an acute-angled triangle; i.e., arelatively slim sectional configuration in which, for example, theheight is larger than 0.9 compared to the width of 1, or the like ispreferred.

In Japanese patent publication (Kokai) 1992-260466, an adhesive agentapplication apparatus, having a triangle-like opening viewed from thefront side thereof formed in the peripheral side of the nozzle as adischarge port for the adhesive agent, and being capable of forming abead having a triangle-like sectional configuration, is disclosed.

However, in the adhesive agent application apparatus, according toexperiments carried out by the inventors, a fact was found that thetopside of the bead tends to be formed flat and a bead having asectional configuration that solves the problem can not formed reliably.The reason of this is why, since the discharge port is formed in theperipheral side of the nozzle, the flow direction of the adhesive agentand the discharge direction thereof cross each other at right angles inthe nozzle; due to this, it is understandable that a large dischargeresistance is given to the adhesive agent at the top end side of thedischarge port when the adhesive agent is discharged therefrom. Further,in case that the bead is applied in a manner of one stroke, it isnecessary that the start and endpoints of the application coincide witheach other accurately. However, with the nozzle having theabove-described configuration, it is extremely difficult to control toachieve the above. Furthermore, for example, in case that the object tobe applied is small like a hard disk cover or the like, in many cases,obstacles (protrusion or rib) may exist adjacent to a flange to beformed with the bead, or the size itself of the flange is small andnarrow. In such circumstances, there may be a case that the bead cannotbe formed using the nozzle having the structure as disclosed in theJapanese patent publication 1992-260466.

DISCLOSURE OF THE INVENTION

The present invention has been proposed in view of the problems and thefindings of the inventor. Accordingly, an object of the invention is toprovide a material application apparatus capable of reliably forming abead that allows a desired deformation by means of a low-pressure forceon the surface of a workpiece.

Another object of the invention is to provide a material applicationapparatus capable of controlling the nozzle to rotate in the peripherydirection thereof even when a movement track for the discharge port isnot in a straight line but in a bent direction to ensure a bead having aspecific sectional configuration anytime.

Still another object of the invention is to provide a materialapplication apparatus capable of applying material along a preset trackwith a high precision without causing any positional displacement of therotational axis even when rotating the nozzle in the periphery directionthereof.

In order to achieve the objects, the invention adopts a constitutionsuch that a material application apparatus that applies-a material froma discharge port of the nozzle along a predetermined movement track onthe surface while performing relative displacement of a surface of aworkpiece disposed on a base and a nozzle with respect to each other,wherein the discharge port is formed into a non-circular configurationand discharges the material so as to form a bead having a sectionalconfiguration in which the height is larger than 0.9 compared to thewidth of 1. By adopting the constitution, flow direction of the materialin the nozzle and the discharge direction thereof substantially coincidewith each other, and it is possible to discharge the material onto thesurface while generally maintaining the configuration of the dischargeport, and a bead allowing a desired deformation with a low pressureforce can be formed reliably on the surface. Herein, it is preferablethat the bead have such sectional configuration that the height islarger than the width.

Also, the invention adopts such constitution that a material applicationapparatus comprises an application means for applying a material to asurface of a workpiece disposed on a base, and a movement means thatmakes the application means perform relative displacement along apredetermined movement track on the surface so as to apply the materialinto a bead configuration, wherein:

the application means includes a syringe and a nozzle connected to thesyringe and provided with a discharge port formed into a non-circularconfiguration;

the nozzle is adapted to be rotatable in the periphery direction thereofin a state that the syringe is not rotated in the periphery directionthereof. By adopting the constitution, when the movement track is set intwo-dimensional directions, i.e., the movement track is set as a closedloop or in a direction along a curved line, it is possible to form abead having a stable sectional configuration by rotating the nozzle inthe periphery direction thereof, while keeping the discharge port in aspecific positional relationship with respect to the surface.Furthermore, since rotation of the syringe in the periphery directionthereof does not accompany, it is possible to be free from a restrictionon the capacity of the syringe.

In the invention, it is preferred to adopt such constitution that thedischarge port is formed into a profile or opening configuration inwhich a first end portion positioned at the front end side in thedirection of the movement along the movement track is wider than asecond end portion positioned at the rear end side in the width in thedirection crossing the movement track. By adopting the constitution, aportion of the bead corresponding to the first end portion of whichwidth in the direction crossing the movement track is wider comes intocontact with the surface prior to the portion of the bead correspondingto the second end portion, and a bead having a sectional configurationin which the top end is smaller than the bottom end in width can beformed reliably. Herein, it is possible to adopt such constitution thatthe nozzle is controlled to rotate so that the first end portionprecedes the second end portion generally throughout the movement track.With this arrangement, it is possible to handle a track havingcurved-portions, such as a closed loop-like track without difficulty.

The invention adopts such constitution that the nozzle is adapted to berotatable in the periphery direction thereof by a motor provided with anoutput shaft positioned generally parallel to the nozzle, and by a driveforce transmission member between the output shaft and the nozzle. Asfor the drive force transmission member, a belt and a gear mechanism forinterconnecting the output shaft and the nozzle to each other areexemplified. By adopting the constitution, since a relatively lightweight member, which is rotated in the periphery direction thereof, isapplicable for the nozzle, a desired performance can be obtained evenwhen a small size motor is adopted. And further, it is possible that thedistance between a drive source and the discharge port can be madecloser to each other to maintain the rotational center axis of thenozzle at a fixed position. As a result, it is possible to apply thematerial discharged from the discharge port precisely along a presetmovement track. Furthermore, the moment of inertia accompanying therotation of the nozzle also can be made smaller and, in this point also,it is possible to reduce the load to the motor.

It is preferred that the discharge port of the nozzle is formed into anacute-angled triangle configuration having abase edge portion and a pairof side edge portions constituting two equilaterals longer than the baseedge portion. In this case, it is adapted so that the nozzle moves withthe base edge portion as the first edge portion and the intersectionpoint of the side edge portions as the second edge portion.

Further, it is preferred that the material is imparted with anappropriate degree of viscosity and thixotropic characteristic tomaintain the application configuration. For example, when forming a beadof which width of the first edge portion is approximately 1-1.5 mm, itis preferred to adopt simultaneously such constitution that degree ofviscosity is set to 10000 cP-400000 cP; while, thixo-index is set to4-10. In this case, when the degree of viscosity is below 10000 cP, theconfiguration at application cannot be maintained. While, when thedegree of viscosity exceeds 400000 cP, the application gets harder, orstringiness of the applied material is caused and a horn-like protrusionmay be formed easily. When the thixo-index is below 4, in this casealso, the configuration cannot be maintained. While, when thethixo-index exceeds 10, stringiness of the applied material is causedand a horn-like protrusion may be formed easily. Further, when theapplied bead is formed into one stroke-like configuration (into aring-like configuration), since the start and end points of theapplication are overlapped with each other, it is preferred to adapt thecharacteristics of the material so that the material fuses together atthe overlapped area.

Furthermore, in order to maintain the configuration at application, itis preferred to adapt the material after taking into consideration thecharacteristics such as, for example, the gravity thereof, the nature ofthe material (in the case of a resin which reacts to moisture and heat,temperature and humidity at application), and the thickness and lengthof the bead to be formed, in addition to the degree of viscosity and thethixo-index.

Still further, it is preferred to adopt such constitution that therelative displacement speed between the surface and the nozzle and thedischarge speed of the material from the discharge port are adapted soas to substantially coincide with each other. With this arrangement, itis possible to form a bead having a sectional configuration, in whichthe height is larger than the width, further reliably.

It is preferred that the space distance between the discharge port andthe surface is set to approximately 1.5-3 times as the height of thebead. When the space distance is under 1.5 times as the height of thebead, the vertex of the bead having the triangle sectional configurationor the like tends to be deformed; while, when the space distance exceeds3 times as the height of the bead, there may be a case that the beadundulates unevenly or deviates from the application position.

In this description, the term “section” applied to the bead means, ifnot otherwise specified, the vertical section in the directionapproximately crossing the extending direction of the bead. Further, theterms “width” and “height” applied to the bead mean the dimensions inthe right and left direction and in the vertical direction respectivelyin the section of the bead shown in FIG. 4.

Furthermore, the term “thixo-index” means a proportion between themeasured values obtained by measuring the degree of viscosity of thematerial while changing the number of revolutions on a viscometer, inparticular, a proportion of viscosity obtained based on the measurementaccording to JISK7117. That is to say, a proportion between the degreeof viscosity at a speed of 2 rotations per minute and the degree ofviscosity at a speed of 20 revolutions per minute measured using aBHtype revolution viscometer (rotor No.7).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view schematically showing a materialapplication apparatus according to a first embodiment of the invention;

FIG. 2 is an enlarged view showing principal parts of FIG. 1;

FIG. 3 is an enlarged perspective view of the front end side of anozzle;

FIG. 4 is a vertical sectional view of a bead;

FIG. 5 is a block diagram illustrating the respective sectionsconstituting a control unit;

FIG. 6 is an enlarged side view illustrating a space distance betweenthe front end of the nozzle and the surface of a workpiece;

FIG. 7 is a view schematically illustrating rotation control of thenozzle;

FIG. 8 is a perspective view schematically showing a materialapplication apparatus according to a second embodiment of the invention;

FIG. 9 is an enlarged view of principal parts of FIG. 8;

FIG. 10 is a perspective view schematically showing a state, in which amaterial is applied to a workpiece;

FIG. 11 is a plan view showing the position of the discharge port on thenozzle when applying the material;

FIG. 12(A) is an enlarged perspective view of the front-end side of anozzle according to a modification of the embodiment;

FIG. 12(B) is a vertical sectional view of a bead, which is formed whena nozzle in FIG. 12(A) is adopted;

FIG. 13(A) is an enlarged perspective view of the front-end side of anozzle according to another modification of the embodiment; and

FIG. 13(B) is a vertical sectional view of a bead, which is formed whenthe nozzle in FIG. 13(A) is adopted.

BEST MODE FOR CARRYING OUT THE INVENTION

Now, embodiments of the invention will be described below with referenceto the attached drawings.

First Embodiment

FIG. 1 is a perspective view schematically showing a materialapplication apparatus according to a first embodiment of the invention;FIG. 2 is an enlarged view showing principal parts of FIG. 1. In thesedrawings, a material application apparatus 10 is an apparatus that formsa bead B on a track L by applying a material such as a sealing agentalong a desired movement track L on a surface S to be applied therewithof a workpiece W. That is to say, the material application apparatus 10comprises a base 11 on which the workpiece W is placed, a syringe 13that applies the material onto the track L, a movement structure 14 thatmoves the syringe 13 in the directions of three orthogonal axes (X-axis,Y-axis and Z-axis in FIG. 1), a rotation mechanism 15 that rotates thesyringe 13 around the axis line of the syringe 13, and a control unit 17that controls a movement structure 14 and a rotation mechanism 15 inaccordance with the track L. The track L in the embodiment is set as aclosed loop forming generally a square in configuration viewed from thetop.

The syringe 13 comprises a main body 18 that stores a material of aresin used as a sealing agent, an adhesive agent or the like, and anozzle 19 provided to the front-end side of the main body 18. It isadapted so that the material is discharged from a discharge port 21formed at the bottom end of the nozzle 19 by pressurizing the materialwithin the main body 18 by means of a pressurizing unit (not shown).Herein, as for the material, one prepared using epoxy resin, siliconresin, urethane resin, acrylate resin, rubber or modified materials ofthem, wherein the degree of viscosity thereof is set to 10000 cP-400000cP and the thixo-index thereof is set to 4-10, is used.

As shown partially in FIG. 3, the nozzle 19 is formed into aconfiguration equipped with a discharge port 21 whose front-end portionpositioned at the left side in FIG. 3 is formed into a generallytriangle pole-like configuration and opens in a configuration of agenerally acute-angled triangle. That is to say, the discharge port 21is formed into a profile, or an opening configuration that includes avertex, or a top portion P at the acute angle side, which is positionedat the top side in FIG. 3; a pair of side edges 23,23, which extendslantwise downwardly from the vertex P in FIG. 3; and a base edgeportion 24, which is connected to the side edges 23,23 at the bottomends thereof in FIG. 3. Owing to the configuration of the discharge port21, it is possible to obtain the bead B that is formed out of thematerial discharged from the discharge port 21, the bead B having, asshown in FIG. 4, an acute-angled triangle sectional configurationgenerally corresponding to the configuration of the discharge port 21;in other words, the bead having a relatively slim sectionalconfiguration in which height H is larger than width BW.

That is to say, according to the embodiment, the width of the base edgeportion 24 of the discharge port 21 is set to about 1.3 mm; while, theshortest distance between the base edge portion 24 and the vertex P,i.e., the height of the discharge port 21 is set to about 1.6 mm. Thebead B, which is formed using the nozzle 19 having the above-describedsize, at a temperature during application set to 25° C., is resulted insuch dimensions that the width BW is about 1.3 mm; and the height H isabout 1.4 mm.

As shown in FIG. 1, the movement structure 14 comprises an X-axis railstructure 26 having a generally gate-like configuration viewed from thelateral side, which extends in the direction of the X-axis in FIG. 1; aY-axis rail structure 27 capable of moving along the X-axis railstructure 26, which extends in the direction of the Y-axis in FIG. 1; aZ-axis rail structure 28 capable of moving along the Y-axis railstructure 27, which extends in the direction of the Z-axis in FIG. 1;and a syringe holder 29 that holds the syringe 13, and that is adoptedto move in the vertical direction with respect to the Z-axis railstructure 28. Herein, although omitted in the drawings, the respectivestructures 26-28 and the syringe holder 29 comprise a drive mechanismsuch-as a motor, a feed screw shaft, a cylinder for operating therelevant mechanism. These motor, cylinder or the like are adopted sothat the control unit 17 controls them. Further, the movement structure14 is not limited to the above-described structure. When the syringe 13can be moved within a predetermined space, another mechanism maybeadopted. For example, although the Y-axis rail structure 28 is supportedat one side in the example shown in the drawings, a structure in which apair of the X-axis rail structures 26 is disposed to support the Y-axisrail structure 28 at both sides; or, a multi-joint arm or the like areexemplified.

The rotation mechanism 15 comprises a motor M that is fixedly disposedwith respect to the syringe holder 29, and it is adapted so that thecontrol unit 17 controls the rotation of the motor M.

As shown in FIG. 5, the control unit 17 is provided with a memory 34that memorizes predetermined data, a movement control section 35 and arotation control section 36 that control the movement structure 14 andthe rotation mechanism 15 based on the data of the memory 34.

The memory 34 is adapted to memorize the track L, obtained by moving thesyringe 13 in manual mode with the front-end side of the nozzle 19(refer to FIG. 1) being faced the workpiece W, as the teaching data.

The movement control section 35 controls the movement structure 14 sothat, after moving the discharge port 21 of the nozzle 19 above thestart point S1 of the track L, the nozzle 19 is moved from the startpoint S1 along the track L while keeping the material in a state beingdischarged from the discharge port 21. Herein as shown in FIGS. 6 and 7,the nozzle 19 is adapted to move over the track L along the same in thecounterclockwise direction, while fixing the space distance D betweenthe discharge port 21 and the surface S to a state of a generallyspecific distance. The space distance D is set to a distance around1.5-3 times of the height H of the bead B (refer to FIG. 4), H being theshortest distance between the vertex P and the base edge portion 24 ofthe discharge port 21. The movement speed of the nozzle 19 along thetrack L is set to a speed that generally coincides with the dischargespeed of the material from the discharge port 21. According to theembodiment, the speed is set to a speed of 50 mm/s or less.

The rotation control section 36 is for controlling the rotation of thenozzle 19 when the nozzle 19 moves along the track L. As shown in FIG.7, the rotation control section 36 controls the rotation of the nozzle19 so that, generally throughout the track L, the base edge portion 24is positioned at the front end side in the direction of movement overthe track L; while, the vertex P is positioned at the rear-end side; andso that the base edge portion 24 crosses the track L approximatelyperpendicular thereto. Owing to this arrangement, the base edge portion24 constitutes a first edge positioned at the front end side in thedirection of movement on the track L; while the vertex P constitutes asecond edge positioned at the rear-end side in the direction of movementon the track L; and the base edge portion 24 of which width in thedirection crossing the track L is wider than that of the vertex P movesover the track L preceding the vertex P.

Next, referring to FIG. 1 and the like, the material applicationoperation in the material application apparatus 10 will be describedbelow.

In a state that the track L is memorized in the control unit 17 as theteaching data, a workpiece W for which the teaching data is used isplaced at a predetermined position of the base 11. When a switch notshown in the drawings is turned ON, the nozzle 19 moves to the startpoint S1 of the track L. And when the discharge port 21 is positionedabove the start point S1, the material begins to be discharged from thedischarge port 21. Keeping the state of discharging, the front-end ofthe nozzle 19 goes around over the track L from the start point S1 inthe counterclockwise direction based on the teaching data. Herein, asshown in FIG. 7, the rotation of the nozzle 19 is controlled so that thebase edge portion 24 of the discharge port 21 always precedes the vertexP. Thus, as shown in FIG. 4, the material applied onto the surface S ofthe workpiece W forms the bead B, having a sectional configuration of agenerally acute-angled triangle configuration corresponding to thedischarge port 21, on the track L. Herein, a part of the bead Bcorresponding to the base edge portion 24 comes into contact with thesurface S; while a portion of the bead B corresponding to the vertex Pis positioned at the top side thereof.

Consequently, according to the embodiment, since the material isdischarged in the same direction as the flow direction of the materialwithin the nozzle 19, and since the configuration of the discharge port21 of the nozzle 19 is formed into a generally acute-angled triangleconfiguration, such effect is obtained that the bead B allowing a largedeformation amount with a smaller pressure force can be formed reliably.

Second Embodiment

FIGS. 8-11 show a second embodiment of the invention. The secondembodiment is characterized in that the nozzle is adapted so as torotate in the periphery direction thereof without rotating the syringein the periphery direction thereof. A material application apparatus 100according to the second embodiment comprises a base 111, an applicationmeans 114 including a syringe 112 and a nozzle 113 that is capable ofmoving along a preset movement track L (refer to FIG. 11) with respectto the surface S of a workpiece W disposed via a table T on the base111, a rotation mechanism 115 that rotates the nozzle 113 in theperiphery direction thereof, and a movement means 116 that moves theapplication means 114 in the directions of three orthogonal axes.

As shown in FIG. 9, the syringe 112 is fixed by brackets 121,121 at twopoints in the axial direction on the upper portion of a holder 120oriented vertically. The syringe 112 is adapted such that a material ofresin, which is used as a sealing agent or an adhesive agent or thelike, is charged via a supply pipe 122 and stored therein; and thematerial stored in the syringe 112 can be discharged from a dischargeport 124 positioned at the bottom end of the nozzle 113 by thepressurizing force by means of a pressurizing unit which is not shown inthe drawings. Herein, the material, the degree of viscosity and thethixo-index are the same as those of the first embodiment.

The nozzle 113 is adapted so that the upper end thereof can rotate inthe periphery direction thereof via a connecting tube 125 disposed atthe bottom side of the syringe 112. The nozzle 113 is supportedrotatably at upper and lower two points via an upper bearing plate 127and a lower bearing plate 128 which are secured at upper and lower twopoints in the lower portion of the holder 120. Supported on the upperface of the upper bearing plate 127 is a motor M capable of rotating inthe forward and reverse directions. An output shaft 130 of the motor Mextends vertically through the upper bearing plate 127 in substantiallyparallel with respect to the nozzle 113. Fixed to the output shaft 130is a pulley 132 while, fixed to the periphery of the nozzle 113 is alarge diameter pulley 133, and attached around between these pulleys132,133 is a belt 134 as a drive force transmission member. Accordingly,by driving the motor M, the nozzle 113 can be rotated in the peripherydirection thereof without rotating the syringe 112 in the peripherydirection thereof. Thus, the rotation mechanism 115 of the nozzle 113comprises the motor M, the pulleys 132,133 and the belt 134. Thedischarge port 124 of the nozzle 113 is the same as that of the firstembodiment.

As shown in FIG. 8, the movement means 116 comprises a support 141adapted so as to be movable in the X-axis direction (right and leftdirection) in FIG. 8 along a rail 140 on the base 111, a slider 144,supported movably in the Y-axis direction (perpendicular direction tothe drawing) along the rail 142 disposed to the upper portion of thesupport 141 in a posture of one-sided support, and the holder 120provided to the slider 144 movably in the vertical direction to hold theapplication means 114. The support 141, the slider 144 and the holder120 according to the second embodiment are controlled in a predeterminedmanner respectively by means of a drive mechanism such as a motor, afeed screw shaft or a cylinder, and a control unit that controls thedrive mechanism entirely (not shown). The movement means 115 is notlimited to the above-described constitution. As long as the syringe 112and the nozzle 113 connected thereto can be made to perform relativedisplacement with respect to the surface S of the workpiece W, anotherconstitution may be adopted. According to the second embodiment,although the syringe 112 and the nozzle 113 are constituted movable inthree orthogonal axes directions, the workpiece W may be alternativelyadapted movable in three orthogonal axes directions.

In a state that the space distance between the discharge port 124 andthe surface S is set at a generally fixed level, the nozzle 113 movesover a preset track. In this case, the space distance, the height H ofthe bead B and the movement speed of the nozzle 113 along the movementtrack L are the same as those of the first embodiment.

When the nozzle moves along-the movement track L, the rotation of thenozzle 113 is controlled so that the base edge portion 136 is positionedat the front edge side in the direction of movement over the movementtrack L, that the vertex P is positioned at the rear-end side thereofand that the base edge portion 136 crosses the track generallyperpendicular thereto in a plane. Owing to this arrangement, the baseedge portion 136 constitutes a first edge portion, which is positionedat the front end side in the direction of movement over the track; thevertex P constitutes a second end portion, which is positioned at therear end side in the direction of movement over the track; and the baseedge portion 136 of which width in the direction crossing the track iswider than that of the vertex P moves along the movement track precedingthe vertex P.

Although omitted in the drawings, according to the second embodiment, apositional fine adjustment mechanism for the discharge port 124 isdisposed adjacent to the application means 114. Owing to this positionalfine adjustment mechanism, it is possible to perform zero-pointadjustment when carrying out initial setting or the like beforebeginning application, and even when an error is generated, it ispossible to carry out correction operation easily.

Next, the material application operation in the material applicationapparatus 100 according to the second embodiment will be describedbelow.

In a state that a workpiece W is positioned as designed on the table T,the nozzle 113 is made to perform a teaching operation to read themovement track previously as the data in the control unit, which is notshown in the drawings. When a switch, which is not shown in thedrawings, is turned ON, as shown in FIG. 11, the nozzle 113, i.e., thedischarge port 124 moves toward the start point S1, and when thedischarge port 124 has been positioned at the start point S1, thedischarge port 124 begins to discharge the material, and whilecontinuing the discharge, the discharge port 124 moves along thepredetermined movement track from the start point S1 based on theteaching data. In this case, even when the movement track is formed intoa curved line configuration as in the areas indicated with A, B and C inFIG. 11, the rotation of the nozzle 113 is controlled so that the baseedge portion 136 of the discharge port 124 always precedes the vertex Pand crosses the movement track. Thus, the material applied on thesurface S of the workpiece W forms a bead B having a sectionalconfiguration like a generally acute-angled triangle corresponding tothe discharge port 124. Herein, a portion of the bead B corresponding tothe base edge portion 136 comes into contact with the surface S, and aportion of the bead B corresponding to the vertex P is positioned at thetop side thereof.

Consequently, according to the second embodiment as described above,since such constitution that the nozzle 113 only is rotated withoutrotating the syringe 112 in the periphery direction thereof is adopted,it is possible to obtain a high speed rotation resulting in an increasedmaterial application efficiency.

As described above, although the best constitution, method and the liketo exploit the invention have been disclosed in the foregoingdescriptions, the invention is not limited thereto.

That is to say, although the invention has been illustrated anddescribed particularly as to mainly specific embodiments, it is possiblefor those skilled in the art, if necessary, to apply a variety ofmodifications on the configuration, position, disposition or the like ofthe embodiments without departing from the scope of the sprit and theobject of the invention. For example, the embodiments adopt suchconstitution that the motor M as a drive source rotates the nozzles 19and 113. However, in the case where the application movement track has agently curved-line configuration, which does not change drastically intwo dimensional directions, it may be arranged such that a protrusion isprovided on the axis of the nozzle and a rod of the cylinder isconnected therewith; and the nozzle is rotated by the forward/reversemovement of the rod.

Also, the configuration of the discharge port 21, 124 of the nozzleaccording to the invention is not limited to the embodiments. Only whena non-circular configuration capable of forming a bead B having asectional configuration, in which the height H is larger than 0.9compared to the width BW of 1, is formed, configuration of a variety ofprofiles may be adopted. For example, as shown in FIG. 12, a dischargeport 200 having an 8-shaped configuration capable of forming a bead Bhaving an 8-shaped sectional configuration, and, as shown in FIG. 13, adischarge port 300 having a trapezoid configuration capable of forming abead B having a trapezoid sectional configuration, are exemplified.

As described above, according to the invention, the discharge port ofthe nozzle-is formed into a non-circular configuration, and it isadapted so as to discharge the material so that a bead having asectional configuration in which the height H is larger than 0.9compared to the width W of 1 can be formed. Therefore, it is madepossible to make the flow direction of the material within the nozzleand the discharge direction substantially coincide with each other; thematerial can be discharged onto the surface while generally maintainingthe configuration of the discharge port; and as a result, a bead thatallows a desirable deformation with a low pressure force can be obtainedreliably.

Also, since such constitution that the nozzle is rotated is adopted, anyproblem does not arise from the capacity or size of the syringe.Accordingly, it is possible to rotate the nozzle at a high speed.Further, owing to that a high-speed rotation is possible, it is possibleto increase the application speed resulting in increased applicationefficiency. Additionally, even when the nozzle is rotated, it ispossible to maintain the rotational axis thereof at the fixed position.Accordingly, it is made possible to apply the material discharged fromthe discharge port along a predetermined track without allowing anypositional displacement. Furthermore, since it is possible to reduce themoment of inertia accompanying the rotation of the nozzle, it ispossible to miniaturize the motor resulting in a cost efficiency and areduction of weight in the application means unit.

Still further, since the discharge port is formed into such profile thatthe first edge portion, which is positioned at the front side in thedirection of movement over the track, becomes wider than the second end,which is positioned at the rear end side, in the width in the directioncrossing the track, it is possible to reliably form a bead that has suchsectional configuration that the upper end is smaller than the lower endin the width thereof.

Still furthermore, since the rotation of the nozzle is controlled sothat the first end portion precedes the second end portion generallythroughout the track, it is possible to handle such track that has curveportions like closed loop track or the like without any trouble.

INDUSTRIAL APPLICABILITY

The invention is applicable generally to apparatus that apply a sealingmaterial to a surface where a various kinds of member is combinedtherewith.

1. A material application apparatus comprising an application means forapplying a material to a surface of a workpiece disposed on a base, anda movement means that makes said application means perform relativedisplacement along a predetermined movement track on said surface so asto apply the material into a bead configuration, wherein: saidapplication means includes a syringe and a nozzle being connected to thesyringe and having a discharge port formed into a non-circularconfiguration; wherein the discharge port of said nozzle is parallel tothe surface and is formed into an acute-angled triangle configurationhaving a base edge portion and a pair of side edge portions constitutingtwo equilaterals longer than the base edge portion, and said nozzle isrotatable in the periphery direction thereof in a state that saidsyringe is not rotated in the peripheral direction thereof.